1. shaped like a triangle or the Greek letter delta (Δ)
Usage: anatomy; geometry

1. the large shoulder muscle that covers the shoulder joint and raises the arm
Usage: anatomy; often called the deltoid muscle

Examples

• The deltoideus muscle is responsible for lifting your arm away from your body.
• Swimmers develop strong deltoideus muscles from repetitive arm movements.
• The deltoideus has a triangular shape when viewed from the side.
• Physical therapists often focus on strengthening the deltoideus after shoulder injuries.
• The deltoideus muscle connects the clavicle, scapula, and humerus.
• Weightlifters target the deltoideus with overhead press exercises.